Transplantation of immortalized CD34+ and CD34-adipose-derived stem cells improve cardiac function and mitigate systemic pro-inflammatory responses

Adipose-derived stem cells (ADSCs) have the potential to differentiate into various cell lineages and they are easily obtainable from patients, which makes them a promising candidate for cell therapy. However, a drawback is their limited life span during in vitro culture. Therefore, hTERT-immortalized CD34+ and CD34-mouse ADSC lines (mADSCs^hTERT) tagged with GFP were established. We evaluated the proliferation capacity, multi-differentiation potential, and secretory profiles of CD34+ and CD34-mADSCs^hTERT in vitro, as well as their effects on cardiac function and systemic inflammation following transplantation into a rat model of acute myocardial infarction (AMI) to assess whether these cells could be used as a novel cell source for regeneration therapy in the cardiovascular field. CD34+ and CD34-mADSCs^hTERT demonstrated phenotypic characteristics andmulti-differentiation potentials similar to those of primary mADSCs. CD34+ mADSCs^hTERT exhibited a higher proliferation ability compared to CD34-mADSCs^hTERT, whereas CD34-mADSCs^hTERT showed a higher osteogenic differentiation potential compared to CD34+ mADSCs^hTERT. Primary mADSCs, CD34+, and CD34-mADSCs^hTERT primarily secreted EGF, TGF-β1, IGF-1, IGF-2, MCP-1, and HGFR. CD34+ mADSCs^hTERT had higher secretion of VEGF and SDF-1 compared to CD34-mADSCs^hTERT. IL-6 secretion was severely reduced in both CD34+ and CD34-mADSCs^hTERT compared to primary mADSCs. Transplantation of CD34+ and CD34-mADSCs^hTERT significantly improved the left ventricular ejection fraction and reduced infarct size compared to AMI-induced rats after 28 days. At 28 days after transplantation, engraftment of CD34+ and CD34-mADSCs^hTERT was confirmed by positive Y chromosome staining, and differentiation of CD34+ and CD34-mADSCs^hTERT into endothelial cells was found in the infarctedmyocardium. Significant decreases were observed in circulating IL-6 levels in CD34+ and CD34-mADSCs^hTERT groups compared to the AMI-induced control group. Transplantation of CD34-mADSCs^hTERT significantly reduced circulating MCP-1 levels compared to the AMI control and CD34+ mADSCs^hTERT groups. GFP-tagged CD34+ and CD34-mADSCs^hTERT are valuable resources for cell differentiation studies in vitro as well as for regeneration therapy in vivo.